A study used a geographical information system (GIS) to assess lake eutrophication. They created a trophic state index (TSI) with six indicators to show the lake's eutrophication level. The study developed a scale from 0 to 100 to classify seven trophic levels in the lake. By using interpolation and GIS overlay techniques, they mapped out the eutrophication levels in the study area. The research discussed the different stages of lake eutrophication over time.